Observations on Superfluid Meniscus in Rotating<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>He-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">B</mml:mi></mml:math>

This paper presents an experimental study on thin liquid drops and films under the combined action of centrifugal forces due to rotation and radial Marangoni forces due to a corresponding temperature gradient. We shall examine thinning of a given liquid layer both with and without rotation and also consider the onset of the fingering instability in a completely wetting liquid drop. In many of the experiments described here, we use an interferometric technique which provides key information on height profiles. For thick rotating films in the absence of a temperature gradient, when an initially thick layer of fluid is spun to angular velocities where the classical Newtonian solution is negative, the fluid never dewets for the case of a completely wetting fluid, but leaves a microscopic uniform wet layer in the center. Similar experiments with a radially inward temperature gradient reveal the evolution of a radial height profile given by h(r) = A(t)r(α), where A(t) decays logarithmically with time, and [Formula: see text]. In the case where there is no rotation, small centrally placed drops show novel retraction behavior under a sufficiently strong temperature gradient. Using the same interferometric arrangement, we observed the onset of the fingering instability of small drops placed at the center of the rotating substrate in the absence of a temperature gradient. At the onset of the instability, the height profile for small drops is more complex than previously assumed.

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“…It is instructive to compare the fringes in this case to the ones in [16]. By counting the fringes, we can reconstruct a profile of the height.…”

Section: Thinning Of a Thick Filmmentioning

confidence: 99%

Wetting dynamics of thin liquid films and drops under Marangoni and centrifugal forces

Mukhopadhyay

Behringer²

2009

J. Phys.: Condens. Matter

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“…Development of surface probes is essential for the surface studies. The macroscopic shape of the free surface under rotation was studied by optical means [5]. The surface dynamics may play a crucial role on the U-tube oscillations [6].…”

mentioning

confidence: 99%

Wigner Solid on the Free Surface of SuperfluidH3e

1997

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We report the measurement of electrical transport of the two-dimensional Wigner solid (WS) formed on the free surface of superfluid 3 He-B down to 230 mK. The resistance R͑T ͒ dramatically decreases as temperature T decreases, obeying Arrhenius' law, R͑T͒~exp͓2D͑T͒͞k B T͔, with D͑T ͒ which we assign to the superfluid energy gap. That is, the scattering of 3 He quasiparticles by the WS determines the transport. The resistance depends systematically on the static electric field which presses the WS toward the liquid surface. We propose that the WS acts as a powerful probe for the study of the superfluid 3 He. [S0031-9007 (97)04553-5] PACS numbers: 67.57.Np, 73.20. -r

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